Review Flashcards: Comprehensive Biology Notes (Digestive, Plant Biology, Genetics, Taxonomy, Biogeochemical Cycles, Photosynthesis & respiration)

These Q&A flashcards cover core topics from the notes: digestive system anatomy and function, plant parts and processes, genetics and crosses, taxonomy and kingdoms, biogeochemical cycles, photosynthesis, and cellular respiration, plus performance-task related concepts.

What is the digestive system's main function?

To break down food, absorb nutrients, and eliminate waste.

What are the two main types of digestion?

Mechanical digestion (physical breakdown) and chemical digestion (enzymes in saliva, stomach acid, etc.).

List the major organs of the digestive tract in order from the mouth to the anus.

Mouth, Pharynx, Esophagus, Stomach, Small Intestine (Duodenum, Jejunum, Ileum), Large Intestine (Colon), Rectum, Anus.

What enzyme is produced by the salivary glands and what does it break down?

Amylase; breaks down starches (e.g., rice, bread).

What are the three sections of the small intestine and their roles?

Duodenum (receives chyme from stomach), Jejunum (major site of absorption), Ileum (absorption of nutrients).

What are villi and what do they do?

Finger-like projections in the small intestine that absorb nutrients into the bloodstream.

What is the function of the large intestine?

Absorbs water and minerals from undigested food and forms solid waste (feces).

Name the accessory organs of digestion and their roles.

Liver (produces bile to digest fats), Gallbladder (stores and releases bile), Pancreas (produces digestive enzymes and insulin).

What does secretion mean in physiology?

The production and release of substances from cells or glands (e.g., saliva, gastric juice).

What are the main digestive processes?

Ingestion, Digestion, Absorption, Assimilation, Egestion.

How do the digestive and circulatory systems work together?

Digestive system prepares nutrients; circulatory system delivers them to cells for energy, growth, and repair.

How do the digestive and excretory systems work together?

Digestive system removes solid waste; excretory system filters blood and removes liquid waste as urine.

What is peristalsis and where does it occur?

Wave-like muscle contractions that move food along the digestive tract; notably in the esophagus.

What is the function of the liver in digestion?

Produces bile to break down fats.

What does the gallbladder do?

Stores bile and releases it into the small intestine.

What does the pancreas do in digestion?

Produces digestive enzymes for fats, carbohydrates, and proteins; also releases insulin to regulate blood sugar.

What is the function of roots in plants?

Anchor the plant, absorb water and minerals, store food, and help growth.

What is the function of stems in plants?

Support the plant; transports water, minerals, and food; stores food in some plants.

What is the function of xylem?

Transports water and dissolved minerals upward from roots to leaves.

What is the function of phloem?

Transports sugars and nutrients from leaves to other parts of the plant.

What is transpiration?

Water vapor released through stomata in leaves; helps in cooling and nutrient transport.

What are stomata?

Small pores on leaves that enable gas exchange and water release.

What are guard cells?

Cells that control the opening and closing of stomata.

What is capillary action and root pressure?

Forces that move water upward through the xylem; example: water rising in celery stalks.

What is translocation in plants?

Movement of sugars from leaves (source) to storage/usage parts (sink) through the phloem.

What are leaves primarily responsible for?

Photosynthesis and transpiration.

What are flowers in plants?

Reproductive organs of the plant.

What are fruits in plants?

Matured ovary after fertilization.

Who is known as the father of genetics?

Gregor Johann Mendel.

What is an allele?

Variant form of a gene; inherited in pairs; can be dominant or recessive.

What is a dominant allele?

One allele is enough to express the trait; represented by capital letters (e.g., B, A).

What is a recessive allele?

Trait expressed only if two recessive alleles are present; represented by lowercase letters (e.g., b, a).

What is genotype vs. phenotype?

Genotype is the genetic makeup (e.g., RR, Rr, rr); phenotype is the physical expression (e.g., round vs wrinkled).

What does homozygous mean?

Having the same alleles (e.g., RR or rr).

What does heterozygous mean?

Having different alleles (e.g., Rr).

What is codominance?

Both alleles are expressed distinctly (e.g., red and white produce red with white spots).

What is incomplete dominance?

An intermediate phenotype is produced (e.g., red + white = pink).

What is a monohybrid cross?

A cross involving one trait; steps include identifying parent genotypes, setting up a Punnett square, filling boxes, and interpreting offspring genotypes/phenotypes.

In a Bb x bb cross, what are the possible genotypes and phenotypes?

Genotypes: Bb and bb in a 1:1 ratio; Phenotypes: 50% black (Bb) and 50% white (bb).

In a Pp x pp cross (purple x white), what are the genotypes and phenotypes?

Genotypes: Pp and pp in a 1:1 ratio; Phenotypes: 50% purple, 50% white.

In a Tt x Tt cross, what is the chance of producing a short plant (short phenotype)?

25% short (tt); 75% tall (TT or Tt).

In a HH x hh cross, what are the offspring like?

All offspring are Hh and will have the dominant phenotype (short hair if H is dominant).

What is a Punnett square used for?

To predict offspring genotypes and phenotypes by combining parental alleles.

What is codominance in genetics?

Both alleles are expressed distinctly (e.g., red and white result in red with white spots).

What is incomplete dominance in genetics?

Heterozygotes have an intermediate phenotype (e.g., pink from red and white).

What are the six kingdoms of life?

Protista, Fungi, Plantae, Animalia, Eubacteria, Archaebacteria.

Why are fungi not considered plants?

Fungi are heterotrophic and absorb nutrients; they do not perform photosynthesis like autotrophic plants.

What is the binomial naming system and who created it?

Genus + species; created by Carl Linnaeus.

Who proposed the three-domain system and on what basis?

Carl Woese; based on differences in ribosomal RNA (rRNA).

What is the hierarchical taxonomic system from broad to specific?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What are the six kingdoms used in classification?

Protista, Fungi, Plantae, Animalia, Eubacteria, Archaebacteria.

Why are fungi distinguished from plants in classification?

Fungi are heterotrophic and absorb nutrients, whereas plants are autotrophic and photosynthesize.

What is a biogeochemical cycle?

Movement of nutrients and elements between biotic (living) and abiotic (non-living) parts of an ecosystem.

What are the main processes of the water cycle?

Evaporation, Transpiration, Condensation, Precipitation, Percolation.

What is the largest source of water vapor in the water cycle?

The oceans (evaporation).

Why is the water cycle important?

Regulates climate and temperature, provides fresh water, and helps purify water.

Name the processes of the carbon cycle.

Photosynthesis, Respiration, Decomposition, Fossil fuel formation, Combustion, Ocean exchange.

Why is the carbon cycle important for life on Earth?

Maintains Earth's temperature and provides carbon for organic molecules.

Which organisms contribute to the oxygen cycle by producing oxygen?

Plants and phytoplankton (phytoplankton contribute about 50% of Earth's O2).

What is nitrogen fixation?

Bacteria convert nitrogen gas (N2) to ammonia (NH3), making it usable by plants.

What is nitrification?

Bacteria convert ammonia to nitrites (NO2-) and then to nitrates (NO3-).

What is assimilation in the nitrogen cycle?

Plants absorb nitrates to build proteins and DNA.

What is ammonification?

Decomposers break organic nitrogen into ammonia.

What is denitrification?

Bacteria convert nitrates back into nitrogen gas, returning it to the atmosphere.

What are the main stages of photosynthesis and where do they occur?

Light-dependent reactions occur in the thylakoid membranes and produce ATP and NADPH with O2 as a byproduct; light-independent reactions (Calvin Cycle) occur in the stroma and synthesize glucose using ATP and NADPH.

Where does the light-dependent reaction occur and what are its main outputs?

In the thylakoid membranes; outputs are ATP, NADPH, and O2.

Where does the Calvin cycle (light-independent reactions) occur and what does it produce?

In the stroma; it uses ATP and NADPH to fix CO2 into glucose.

What factors affect the rate of photosynthesis?

Sunlight (intensity), temperature (optimum range 25–35 °C), and carbon dioxide concentration.

What is cellular respiration?

The process by which cells break down organic molecules (e.g., glucose) to produce ATP, primarily in mitochondria.

What are the two main types of cellular respiration?

Aerobic respiration (needs oxygen) and anaerobic respiration (occurs without oxygen).

What are the main stages of aerobic respiration and their ATP yields?

Glycolysis in the cytoplasm (2 ATP, 2 NADH); Krebs Cycle (2 ATP, 6 NADH, 2 FADH2); Electron Transport Chain (about 32–36 ATP); total ≈32–38 ATP per glucose.

What is lactic acid fermentation and when does it occur?

Anaerobic fermentation that occurs in muscle cells during intense exercise; produces lactic acid leading to fatigue.

What is alcoholic fermentation and where does it occur?

Fermentation that produces ethanol and CO2; occurs in yeast and some bacteria; used in bread making and alcoholic beverages.

What is starch testing (iodine test) and what indicates a positive result?

Iodine solution reacts with starch to yield a blue-black color; blue-black indicates starch presence.

What does Benedict’s test detect and what indicates higher sugar content?

Detects reducing sugars; color changes from blue to green/yellow/orange/red as sugar concentration increases; brick-red indicates high glucose.